Claude adds two invisible marks to AI output

Anthropic says it will mark Claude-generated content with two invisible signals: an imperceptible watermark woven into supported text and signed C2PA provenance metadata attached to supported .svg, .png, and .jpg files. Its support documentation says the text mark travels with copied text and may survive some edits, while reporting on the rollout says new Claude models will mark output from launch but support for existing models remains in progress. The marks apply at the model level across Claude surfaces and cloud deployments; detection details are still forthcoming. Teams shipping Claude output should treat provenance as a traceability layer—not proof of authorship—because metadata can be stripped and the text detector’s robustness is unreported, then retain their own model and version logs alongside the archive’s EU transparency checklist.